use iframe in Vaadin Window instead of native window
actuall update user information in initialization
avoid possible null pointer exception if not logged in
more nullpointer checks
Merged 'develop'.

Conflicts:
	annis-gui/src/main/java/annis/gui/SearchUI.java
	annis-gui/src/main/java/annis/gui/resultview/ResultViewPanel.java
refactoring the login window in order to allow browsers to remember the password, fixes #7